Content uniformity is a regulatory concern for all finished pharmaceutical products. This is particularly true for solid oral dosage forms such as tablets and capsules. While typical regulatory requirements may not be as rigorous for nutritional supplements such as vitamins, where vitamins are packaged with another pharmaceutical product, content uniformity requirements become rigorous for all components.
Anytime that a vitamin is added to any pharmaceutical formulation it will be present in very low quantities by weight (typically from 0.001 to 0.05 percent). Therefore meeting the pharmaceutical requirements for content uniformity of <6% relative standard deviation (RSD) is a major challenge. Most of the combination vitamin products on the market today only have to meet nutritional standards that have no content uniformity requirement. Typical calcium plus vitamin D nutritional products currently on the market have content uniformity for vitamin D of 7-15% RSD. The FDA has been clear that any pharmaceutical product or nutritional product packaged with another pharmaceutical product must meet all pharmaceutical specifications. Formulations of calcium carbonate and vitamin D have been problematic in terms of acceptable content uniformity.
Dosage forms comprising vitamin D have been discussed in the prior art. Much of the prior art has been concerned with the stability of vitamin D dosage forms. Makino et al, in U.S. Pat. No. 4,729,895 teaches solid pharmaceutical preparations of vitamins D3 prepared by forming an outer layer comprising vitamin D3 and an excipient, which is readily soluble in an organic solvent, around an inner layer comprising an excipient which is slightly soluble in an organic solvent. Makino teaches markedly improved stability for such solid pharmaceutical preparations of vitamins D3.
In U.S. Pat. No. 5,328,903, Ishii, et al. teaches a composition for solid pharmaceutical dosage forms of vitamin D in which the vitamin D is uniformly distributed in the composition. The composition comprises an excipient comprising mannitol and/or sugar; a degradative agent comprising hydroxypropyl cellulose; and/or a binder comprising polyvinyl pyrrolidone and/or hydroxypropylmethyl cellulose.
In PCT publication WO 92/09271, Wozny, et al. teaches solid pharmaceutical preparations containing vitamin D3 which are significantly stabilized. The compositions include hydroxypropylmethyl cellulose to which is attached active vitamin D3 and a polymer which is readily soluble in an organic solvent.
The inventors have found that by modifying the formulation, raw material specifications, and the process, we can improve the content uniformity and meet pharmaceutical specifications.